package com.atguigu.springcloud.lb;

import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * 手写轮询算法
 */
@Component
public class MyLB implements LoadBalancer {
    private AtomicInteger atomicInteger=new AtomicInteger(0);

    public final int getAndIncrement(){
        int current;
        int next;
        do {
            current=this.atomicInteger.get();
            next=current>=2147483647?0:current+1;

        }while (!this.atomicInteger.compareAndSet(current,next));
        System.out.println("*******第几次访问,次数next:"+next);
        return next;
    }

    @Override
    public ServiceInstance instances(List<ServiceInstance> serviceInstances) {

        int index = getAndIncrement() % serviceInstances.size();
        return serviceInstances.get(index);
    }
}
